Natural disinfectants

Title

Natural Disinfectants

Problem Scenario
I want people to have safe, healthy ways to disinfect their house instead of using harmful chemicals.
Broad Question

What effect do natural disinfectants have on bacteria?

Specific Question

What effect do vinegar, citric acid, and alcohol have on bacteria?

Hypothesis
All the disinfectants will have a negative effect on the bacteria by killing them but, the alcohol will kill the most bacteria out of the four disinfectants. The Clorox will kill the second most bacteria, the vinegar will kill the third most, and the citric acid will kill the least amount of bacteria.
Graph of Hypothesis

Variables

Independent Variable:

The disinfectant used.

Dependent Variable:

The amount of bacteria alive.

Variables That Need To Be Controlled:

The amount of disinfectant used to clean the areas.

Vocabulary List That Needs Explanation

Culture- The act or process of growing living material, usually bacteria or viruses, in prepared nutrient media.
Bacteria- One-celled organisms that are spiral, spherical, or rod-shaped and appear singly or in chains. Various species that are involved in fermentation, infectious diseases, nitrogen fixation, or putrefaction.
Disinfectant- A chemical agent used chiefly on inanimate objects to destroy or inhibit the growth of harmful organisms.
Colony Forming Units (CFU)- A measure of viable bacterial of fungal numbers in microbiology.
pH- pH is a figure expressing the acidity of a solution.
Biofilm-A structure adhering to surfaces that are often in contact with water. They consist of colonies of bacteria and other microorganisms that secrete a protective coating, in which they encase them selves in, to be protected from forms of disinfection and the natural world.
Bacteriostatic-A substance that inhibits the growth or multiplication of bacteria.
Bactericide- A substance that kills bacteria.

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General Plan

I'm going to take 4 samples of the kitchen .Next I'm going to clean a small section of the kitchen counter, and bathroom floor with alcohol, citric acid, vinegar, an Clorox. I'm then going to take four samples (citric acid, vinegar, alcohol, and Clorox) from all four areas to culture 30 minutes later. I am then going to take the same samples 72 hours later. I'm then going to culture all the samples. After the trays are cultured I'm then going to measure the amount of bacteria killed in the trays with the disinfectants. I'm then going to compare the trays with the disinfectant to the trays with the Clorox and see which disinfectant kills the most bacteria.

Potential Problems And Solutions

-I may not have all the culture trays for the start of my experiment. While I am waiting for more culture trays I will do background research and start the experiment as much as I can.
-I may not have all the disinfectants on the 15th, so I will use the disinfectant I don't have, last.
-The culture trays might dry out, so I will use them before they dry out.

Safety Or Environmental Concerns

-Safety- I am using and growing bacteria for my experiment so I have to use the bacteria safely.

Experimental Design

(add the correct headings from the experimental design page before beginning)

What is your experimental unit?

My experimental unit will be 1 CFU (Colony Forming Units). I will be measuring the visual coverage of bacteria.

Number Of Trials:

I will have two trials. The trials will be on the floor and counter.

Number Of Subjects In Each trial:

I will have 4 subjects in each trial.

Number of Observations:

I will take 4 observations for each trial.

When data will be collected

The data will be collected between Feb. 20 and 28.

Where will data be collected?:

The data will be collected at my house.

Resources and Budget Table

Item	Number needed	Where I will get this	Cost
poster board	1	store	$5
white vinegar	1 bottle	house	free
blood agar trays	24	hospital	$6
lemons	1	house	free
bacteria	unknown	around the house	free
rubbing alcohol	1 bottle	house	free
Clorox Wipes	1 container	house	free

Detailed Procedure
1.Take 4 samples of a a section of the kitchen counter and bathroom floor to use as a control.
3.Clean a small section of the counter and floor with the vinegar. Take a sample of each area 30 minutes later.
3.Clean a small section of the counter and floor with the alcohol. Take a sample of each area 30 minutes later.
4.Clean a small section of the counter and floor with lemon juice as the citric acid. Take a sample of each area 30 minutes later.
5.Clean a small section of the counter and floor with the Clorox. Take a sample of each area 30 minutes later.
6. Culture the samples.
7.Take all samples again, 72 hours later.
8.Culture the second samples.
9.Measure the amount of of visible bacteria in the trays in CFU's.
10.Compare the results of the trays with the natural disinfectants to the trays with the Clorox.
11.See which disinfectant got rid the most bacteria for the longest time.
Diagram

Photo List

-All bacterial samples with the Clorox after they are cultured.
-All bacterial samples with the vinegar after they are cultured.
-All bacterial samples with the citric acid after they are cultured.
-All bacterial samples with the alcohol after they are cultured.
-Areas I'm cleaning.

Time Line

February 5-14- I will gather all my materials
February 15- I will start the experiment at home.
February 15-25- I will have all the photos taken.
February 25- I will have my completed experiment.
March 22- I will have finished my poster board.

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Data Table
CFU's (Colony Forming Units)
1=0-20
2=20-50
3=50-100
4=100+
Counter

Clorox Ctrl	4
Vinegar Ctrl	4
Citric Acid Ctrl	4
Alcohol Ctrl	4
Clorox 30 Mins	1
Vinegar 30 Mins	4
Citric Acid 30 Mins	3
Alcohol 30 Mins	3
Clorox 72 Hrs.	3
Vinegar 72 Hrs.	4
Citric Acid 72 Hrs.	2
Alcohol 72 Hrs.	4

Floor

Clorox Ctrl.	4
Vinegar Ctrl.	4
Citric Acid Ctrl.	4
Alcohol Ctrl.	4
Clorox 30 Mins.	1
Vinegar 30 Mins.	3
Citric Acid 30 Mins.	1
Alcohol 30 Mins.	1
Clorox 72 Hrs.	4
Vinegar 72 Hrs.	4
Citric Acid 72 Hrs.	4
Alcohol 72 Hrs.	4

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Data Analysis

All Raw Data

Counter:
Control Before-100+
Vinegar Before-100+
Alcohol Before-100+Citric Acid Before-100+
Control 30 Mins-0-20
Vinegar 30 Mins-100+
Citric Acid 30 Mins-50-100
Alcohol 30 Mins-50-100
Control 72 Hrs-50-100
Vinegar 72 Hrs-100+
Citric Acid 72 Hrs-20-50
Alcohol 72 Hrs-100+
Floor:
Control Before-100+
Vinegar Before-100+
Citric Acid Before-100+
Control 30 Mins-0-20
Alcohol Before-100+
Vinegar 30 Mins-50-100
Citric Acid 30 Mins-0-20
Alcohol 30 Mins-0-20
Control 72 Hrs-100+
Vinegar 72 Hrs-100+
Citric Acid 72 Hrs-100+
Alcohol 72 Hrs-100+
Graphs


Photos

Results

Vinegar was the worst disinfectant out of the four disinfectants. On the counter it got a 3 on at 30 mins, and a 4 at 72 hours. On the floor it got a 3 at 30 mins, and a 4 at 72 hours. Citric Acid was the best disinfectant. On the counter it got a 3 at 30 mins, and a 2 at 72 hours. On the floor it got a 1 at 30 mins, and a 4 at 72 hours. Clorox was the second best disinfectant. On the counter it got a 1 at 30 mins, and a 3 at 72 hours. On the floor it got a 1 at 30 mins, and a 4 at 72 hours. Alcohol was the second worst disinfectant. On the counter it got a 3 at 30 mins, and 4 at 72 hours. On the floor it got a 1 at 30 mins, and a 4 at 72 hours.
Conclusion
I hypothesized that all the disinfectants would have a negative effect on the bacteria, with the alcohol would have the biggest effect, the Clorox would have the second biggest effect, the vinegar would have the second smallest effect, and the citric acid would be have the smallest effect. I disagree with my hypothesis because it was almost completely wrong. All the disinfectants ended up having a negative effect on the bacteria, whether large or small, but the citric acid ended up being the best disinfectant, the Clorox was the second best disinfectant, the alcohol was the second worst disinfectant, and the vinegar was the worst disinfectant. On the floor all the disinfectants had a 4 (100+ CFU's) at 72 hours. At 30 minutes the citric acid had a 1 (0-20 CFU's), the Clorox had a 1, the vinegar had a 4, and the alcohol had a 1. On the counter at 30 minutes the citric acid had a 3 (50-100 CFU's), the Clorox had a 1, the vinegar had a 3, and the alcohol had a 3. At 72 hours the citric acid had a 2(20-50 CFU's), the Clorox had a 3, the vinegar had a 4, and the alcohol had a 4.

Discussion

All the disinfectants had a negative effect on the bacteria but, vinegar was the worst, getting a 3 (50- 100 CFU's) at 30 minutes and a 4 (100+) at 72 hours on the counter. On the floor it got a 4 at 30 minutes and a 4 at 72 hours. Alcohol was the second worst disinfectant getting a 3 at 30 minutes and a 4 at 72 hours on the counter. On the floor it got a 1 (0-20 CFU's) at 30 minutes and a 4 at 72 hours. Clorox was the second best disinfectant getting a 1 at 30 minutes and a 3 at 72 hours on the counter. On the floor it got a 1 at 30 minutes and a 4 at 72 hours. Citric acid was best of the four disinfectants, getting a 3 at 30 minutes and a 2 (20-50 CFU's) at 72 hours on the counter. On the floor it got a 1 at 30 minutes and a 4 at 72 hours. My hypothesis was mostly incorrect. I said that the alcohol would be the best disinfectant but it turned out to be the second worst disinfectant. The best disinfectant was the citric acid, which I hypothesized to be the worst disinfectant because of it's sugar content. The worst disinfectant turned out to be the vinegar, which I thought would be the second worst disinfectant. I think the vinegar was the worst disinfectant because I used distilled white vinegar, which is less acidic then regular white vinegar. Finally the second best disinfectant was the Clorox which, I hypothesized to be the second best disinfectant. My experiment can be improved by using the most acidic vinegar, citric acid, and alcohol possible. I could also isolate the areas I'm cleaning so there is no possible way for the sections I cleaned to be tampered with. In my experiment the all the sections I cleaned on the counter may have been tampered with. I don't think it would throw my data off much because all the sections might have been tampered with the same amount.
Benefit to Community and/or Science
My experiment can help us learn more about biofilms, how we can remove them in faster more effective ways, and what the best acidity for removing biofilms is. People could also start using a cheaper, chemical free disinfectant that disinfects better than chemicals.
Background Research
Bacteria are microscopic organisms that are generally made up of one cell and don't have a nucleus. Bacteria are sorted into four groups based on their shape, rodlike (bacillus), spherical (coccus), spiral or corkscrew (spirilla), and comma shaped (vibrio). Bacteria usually multiply in the process of fission, in which a single cell divides into two new cells. Bacteria divide once every 15 minutes-16 hours, depending on the type of bacteria. Moisture, temperature, and pH are the most important factors that influence bacterial growth. Most bacteria thrive at 37 degrees Celsius, but some thrive at 0-200 degrees Celsius. Most bacteria need a pH between 6.7 and 7.5. Bacteria have a very protective coating called biofilms. Biofilms protect bacteria from the environment and forms of disinfecting. To disinfectant something the disinfectant must first breakdown the biofilm, and to do this it has to be in contact with it for 10-30 minutes. After the biofilm it gone the disinfectant then either kills or inhibits growth depending on whether it is a bactericide or a bacteriostatic agent.
References
"Bacteria." UXL Encyclopedia of Science. 2002. Encyclopedia.com. 11 Mar. 2013 <http://www.encyclopedia.com>.
www.emlab.com/s/sampling/2010-04-Biofilms.html
http://medical-dictionary.thefreedictionary.com
Abstract
Are there natural disinfectants out there?

Eric Bormann

Bacteria has long been a problem to humans causing many problems. Today, we use chemicals to disinfect our homes, stopping many of the problems they cause. But most the chemicals we use are expensive and toxic to us.

In my experiment I wanted to see what effect natural disinfectants had on bacteria. I hypothesized that out of the four disinfectants, the alcohol would have the biggest effect. The Clorox would have the second biggest effect, the vinegar the third, and the lemon juice the smallest effect.

To do this, I took four samples of my bathroom floor and kitchen counter. Next, I cleaned the sections on the floor and counter with lemon juice, distilled white vinegar, alcohol, and Clorox. I then took the same samples again 30 minutes and 72 hours after I cleaned. Next, I had them incubated at the hospital. Finally I counted up the average number of Colony Forming Units (CFU’s), sorting them into groups of 1 (0-20 CFU’s), 2 (20-50 CFU’s), 3 (50-100 CFU’s), and 4 (100+ CFU’s)
My results showed that all four disinfectants had a negative effect on the bacteria, but lemon juice had the biggest effect. The Clorox had the second biggest effect, alcohol had the third, and vinegar the smallest effect out of all four disinfectants.